The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to figure out when it's the best time to plant nigella by referring to the USDA zone info for Vail.

Planting Calendar for Nigella

Frost tolerance for nigella:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since nigella are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant nigella in Vail is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant nigella and expect a good harvest is probably August. Any later than that and your nigella may not have a chance to fully mature. If you are starting your nigella indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost is on May 15 in Vail. It might get as low as -25°F during the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Vail and it changes from year to year. Since half of the time in Vail it frosts late in the year after May 15 be ready to cover your nigella if you have one of those late frosts.

USDA Zone Info for Vail

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Vail

You may be interested in your other planting guides for Vail.